1. Field of the Invention
The present invention relates generally to a mounting arrangement for a dual sleeve boiler and, more particularly, to a mounting arrangement which provides a thermal barrier between a heat producing portion of the boiler and the mounting portion of the boiler.
2. Description of the Related Art
Many different types of boilers and heat exchangers are known to those skilled in the art. Typically, a source of heat is provided for the purpose of raising the temperature of a fluid that is passing through a heat exchanging portion of the boiler. This source of heat can be in the form of combustion, wherein a fuel is burned, or, alternatively, in the form of a chemical reaction resulting from the mixing of various chemicals for the purpose of raising the temperature in a combustion chamber of the boiler. In other types of heat exchangers, the device can employ two or more fluid flow paths which are separated from each other, but which pass in close proximity with each other within the heat exchanger for the purpose of transferring heat from one fluid to another. In this type of heat exchanger, the primary source of heat is external to the heat exchanger and a first fluid is heated by the primary source of heat. This first fluid is then circulated through one or more conduits within the heat exchanger in close proximity with a second fluid passing through different conduits within the structure of the heat exchanger.
U.S. Pat. No. 4,644,906, which issued to Garabedian et al on Feb. 24, 1987, discloses a double tube helical coil steam generator in which a multiplicity of inner tubes are provided to conduct water. These inner tubes are individually surrounded by outer tubes containing liquid metal as a heat transfer agent. In this device immersion of the double tube helical coil in the hot liquid metal causes efficient transfer of heat across the liquid metal in the outer tube to the water in the inner tube for the purpose of creating superheated steam.
U.S. Pat. No. 4,446,820, which issued to Jansing et al on May 8, 1984, discloses a steam generator which is heated by liquid metal. Typically used in nuclear power plants, this steam generator comprises several coiled tube bundles which are arranged in series and disposed in a common container in which steam is generated and superheated.
U.S. Pat. No. 4,433,722, which issued to Fueglister on Feb. 28, 1984, discloses a heat exchanger which has pipe coils that are supported in support plates. This patent describes a thin walled resilient sleeve which is disposed between each group of support plates and a pipe at the center of the pipe coils. The sleeves of this heat exchanger enable the support plates, which become hotter than the pipe coils during operation, to expand toward the central pipe for the purpose of reducing the heat expansion of the pipe coils and the resulting bending stresses.
U.S. Pat. No. 4,307,685, which issued to Robin et al on Dec. 29, 1981, discloses a heat exchanger for use with a sodium heated steam generator. This device comprises a vertical outer cylindrical shell, a distributor for supplying the inner space of the shell with liquid sodium and at least one tube bundle disposed within the shell for circulating water in heat exchange relation with the sodium. It also comprises a means for maintaining an inner gas atmosphere above a predetermined free level of liquid sodium. The top and bottom tube ends are fitted with thermal sleeves for joining them to the lateral wall of the shell and passing them through this shell.
U.S. Pat. No. 4,137,967, which issued to Hirschle on Feb. 6, 1979, discloses a steam generator with expansion pipe loops which connect the tubes of the heat exchanger to the discharge lines. The pipe loops are suspended by double armed levers which are movably secured at the ends of the mounting system and anchoring system of the steam generator. The portions of the pipe loops which are connected to the fulcrum of the respective levers, as well as the fulcrums themselves, are chosen to render the stresses in the pipe loops as low as possible and approximately equal on both sides of pivots.
U.S. Pat. No. 4,552,211, which issued to Weber on Nov. 12, 1985, discloses a heat exchanger with convection suppressing longitudinal baffles. This patent describes a heat exchanger which has a vertical central tube and a concentric jacket between which the support plates extend radially and axially. The support plates carry a plurality of heat exchanger tubes and the jacket is formed near the top and bottom ends with apertures for a heat yielding medium which flows around the heat exchanger tubes.
U.S. Pat. No. 4,624,304, which issued to Hayes on Nov. 25, 1986, discloses an expandable support for insertion into a tube bundle. Flattened tubes are inserted between each layer of tubes in the tube bend region of a shell and tube type heat exchanger. The flattened tubes are then pressurized to expand them in the region below the tube bend so that they lock the support plates into place for the purpose of preventing them from vibrating and causing damage to the tubes in the first rows of the tube bundle.
U.S. Pat. No. 3,921,708, which issued to Brenner on Nov. 25, 1975, describes a heat exchanger in which an element under internal pressure is a thin walled flexible tube whose inner and outer surfaces have the form of corrugations with supporting means. These act to limit the expansion of the flexible tube to prevent deflection from the longitudinal axis.
U.S. Pat. No. 3,720,259, which issued to Fritz et al on Mar. 13, 1973, discloses a tubular heat exchanger supporting and spacer structure. Spirally wound tubes are arranged next to each other surrounding a given axis with convolutions of one tube axially aligned with the convolutions of the adjacent tube. These tubes form a group having an inner region directed toward the latter axis and an outer region directed away from the latter axis. This spacer structure serves to transmit to the supporting structure the weight of the tubes and the spacer structure as well as any thermal or mechanical stresses or reaction forces resulting from flow of the fluids during operation of the heat exchanger.
U.S. Pat. No. 3,964,416, which issued to Kiraly et al on June 22, 1976, discloses a boiler reactor which comprises a cylindrical casing with closures at its opposite ends. Also, a steam generating tube is provided and disposed adjacent the inner surface of the casing.
U.S. Pat. No. 3,100,523, which issued to Marrujo on Aug. 13, 1963, discloses a heat exchanger with a helical coil. This heat exchanger comprises a base which has an integrally formed upstanding tubular wall around its outer periphery. The cylindrical wall has an external tapered surface about which is disposed a helically wound conduit or heat exchanger coil.
U.S. Pat. No. 1,224,105, which issued to Davison on Apr. 24, 1917, discloses a water tube boiler for use with submarines. This boiler provides an inner hull adapted to contain fore and aft of the boiler compartment various subdivisions of the interior of the inner hull to establish battery compartments, cruise quarters, engine room, etc. The fire box of the boiler is double ended so that gases from the burners may be caused to circulate among the tubes by means of suitably arranged baffles before entering an uptake portion.
Dual sleeve boilers are generally known to those skilled in the art. In certain types of these boilers, tubes are helically wound around a centerline to define a cylinder. The tubes can be would tightly with each of the turns of the helix being in contact with adjacent turns to permit the turns to be attached together by some appropriate means, such as welding, for the purpose of forming a generally impermiable cylinder with the walls of the cylinder comprising the tubes themselves. If two of these cylinder structures are disposed in coaxial and concentric relation with each other, a generally annular space can be formed therebetween in which a heat generating reaction can be contained. With the addition of end caps, or some means of enclosing the ends of the annular space, a confined region can be defined within the annular space for the purpose of containing a heat generating reaction which can be a form of combustion or a heat generating chemical reaction. A fluid can be directed through the tubes of both the inner and outer cylindrical structures for the purpose of absorbing heat from the reaction occurring within the annular space.